Low Temperature Sodium-Sulfur Grid Storage and EV Battery

Berkeley Lab researcher Gao Liu has developed an innovative design for a battery, made primarily of sodium and sulfur, that holds promise for both large-scale grid storage systems and for consumer products such as residential photovoltaic systems. The cathode is made of sulfur and a conductive polymer, while the solid electrolyte — based on cross-linked polyethylene oxide — forms a stable but ion-conducting barrier separating the liquid sodium anode.

Description

A key feature of this sodium sulfur battery is its low operating temperature. Conventional high temperature sodium sulfur batteries require temperatures of 300–350°C, and as such are only suitable for grid storage applications. The Berkeley Lab design operates as low as 60°C, and is corrosion resistant. Yet, its specially designed sodium anode will not form dendrites, which cause short circuits and are a significant problem in low temperature sodium sulfur battery designs.

Large and reliable storage battery systems are essential for electrical grids supporting sustainable energy sources such as wind and solar power, where peak production hours may not match hours of peak demand. The Berkeley Lab technology is a cost effective solution that relies on Earth-abundant materials. The design is readily scalable so it can work in both large and small applications.